|Title||"A COMPARISON BETWEEN SPECTRAL DOMAIN AND TIME DOMAIN OCT IN GLAUCOMA": A PILOT STUDY|
|Author, Co-Author||Adam Sloane, Renee Klein|
|Abstract|| PURPOSE: Spectral Domain Optical Coherence Tomography (SD-OCT) technology affords greater imaging speed and resolution over current Time Domain (TD-OCT) technology. It is not yet fully understood how the newer retinal nerve fiber layer (RNFL) measurements of the SD-OCT relate to those of the TD-OCT. A pilot study was designed to determine if a difference exists between the two devices in the area of RNFL assessment and the detection of early glaucoma.
METHODS: Fast RNFL thickness scans on Stratus OCT and Nerve Head Map (NHM4) on RTVue were performed on 17 eyes of 11 individuals with early glaucoma (defined by glaucomatous optic nerve changes or glaucomatous visual field changes with mean deviation < -6db) and 28 normal eyes of 15 individuals. Correlation between thickness measurements and visual field indices were calculated and compared for glaucoma and control groups.
RESULTS: RTVue RNFL thickness measurements were on average thicker than Stratus measurements, but there was significant variability. RTVue and Stratus correlated most strongly in average thickness measurements and in measurements of the inferior quadrant (.93 and .89 respectively). When compared with visual fields, RTVue and Stratus correlated equally highly with mean deviation in the inferior quadrant (.58), while the next strongest correlation was between mean deviation and average thickness with RTVue having a stronger correlation than Stratus (.41 and .26 respectively).
CONCLUSIONS: While the two devices were highly correlated, they were not interchangeable. The strongest correlations were in the inferior quadrant and average thickness, which is in agreement with other early studies. Of the measurements where thickness and visual field indices had significant correlations, the RTVue performed as well (inferior quadrant) or slightly better than the Stratus (average thickness). There were areas with weak to no correlation between thickness and visual field indices, which is likely due to known discrepancies in the relationship between structure and function in this population.
|Affiliation of Co-Authors||Department of VA New York Harbor Health Care System|